Purpose :
To assess corneal biomechanical behavior using a modified technique for optical coherence elastography (OCE) in its first in vivo application.

Methods :
A previously described corneal elastography technique (Ford et al., JBO 2011) based on optical coherence tomography was modified and applied for the first time in an IRB-approved human subjects study. Corneal deformations are delivered using a flat lens attached to a linear actuator and rapid-sampling force transducers over a two-second perturbation. A cross-correlation algorithm is applied to track frame-by-frame intrastromal speckle displacement. Regional displacements for the anterior and posterior stroma were determined using custom software, and data were plotted in a force vs. displacement graph. Total displacement was defined as the vector sum of horizontal and vertical displacements, for both the anterior and posterior corneas. A displacement/force relationship was established by dividing the maximum total displacement by the maximum force for the anterior (Ka) and posterior cornea (Kp).